20,441 research outputs found

    Water management subsystem specification for space flights of extended time periods. Life support system for space flights of extended time periods

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    Water management subsystem of life support system for manned space flight specification

    Ternary inorganic compounds containing carbon, nitrogen, and oxygen at high pressures

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    Ternary C_{x}N_{y}O_{z} compounds are actively researched as novel high energy density and ultrahard materials. Although some synthesis work has been performed at ambient conditions, very little is known about the high pressure chemistry of of C_{x}N_{y}O_{z} compounds. In this work, first principles variable-composition evolutionary structure prediction calculations are performed with the goal of discovering novel mixed C_{x}N_{y}O_{z} materials at ambient and high pressure conditions. By systematically searching ternary variable composition crystalline materials, the full ternary phase diagram is constructed in the range of pressures from 0 to 100 GPa. The search finds the C_{2}N_{2}O crystal containing extended covalent network of C, N, and O atoms, having space group symmetry Cmc2_{1}, and stable above just 10 GPa. Several other novel metastable (CO)_{x}-(N)_{y} crystalline compounds discovered during the search, including two polymorphs of C_{2}NO_{2} and two polymorphs of C_{3}N_{2}O_{3} crystals are found to be energetically favorable compared to polymeric carbon monoxide (CO) and nitrogen. Predicted new compounds are characterized by their Raman spectra and equations of state

    A study of A8 and A2 migrants in Nottingham

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    The research was commissioned by Nottingham City Council and One Nottingham in August 2008 and was conducted by a team of researchers from the Salford Housing & Urban Studies Unit at the University of Salford. The study was greatly aided by research support from Nottingham City Council Children’s Services Asylum Seeker/Refugee Support Team, as well as a number of community interviewers. The project was managed by a steering group composed of officers representing Nottingham City Council, One Nottingham, Nottingham City Homes, NHS Nottingham City, Nottinghamshire Fire & Rescue Service, Nottinghamshire Police and Basic Educational Guidance in Nottinghamshire (BEGIN). The main objective of this research was to explore the needs and experiences of A8 and A2 migrants living and working in Nottingham

    Novel Potassium Polynitrides at High Pressures

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    Polynitrogen compounds have attracted great interest due to their potential applications as high energy density materials. Most recently, a rich variety of alkali polynitrogens (R_{x}N_{y}; R=Li, Na, and Cs) have been predicted to be stable at high pressures and one of them, CsN_{5} has been recently synthesized. In this work, various potassium polynitrides are investigated using first-principles crystal structure search methods. Several novel molecular crystals consisting of N_{4} chains, N_{5} rings, and N_{6} rings stable at high pressures are discovered. In addition, an unusual nitrogen-rich metallic crystal with stoichiometry K_{2}N_{16} consisting of a planar two-dimensional extended network of nitrogen atoms arranged in fused eighteen atom rings is found to be stable above 70 GPa. An appreciable electron transfer from K to N atoms is responsible for the appearance of unexpected chemical bonding in these crystals. The thermodynamic stability and high pressure phase diagram is constructed. The electronic and vibrational properties of the layered polynitrogen K_{2}N_{16} compound are investigated, and the pressure-dependent IR-spectrum is obtained to assist in experimental discovery of this new high-nitrogen content material

    Pentazole and Ammonium Pentazolate: Crystalline Hydro-Nitrogens at High Pressure

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    Two new crystalline compounds, pentazole (N_{5}H) and ammonium pentazolate (NH_{4})(N_{5}), both featuring cyclo-{\rm N_{5}^{-}} are discovered using first principles evolutionary search of the nitrogen-rich portion of the hydro-nitrogen binary phase diagram (N_{x}H_{y}, x\geqy) at high pressures. Both crystals consist of the pentazolate N_{5}^{-} anion and ammonium NH_{4}^{+} or hydrogen H^{+} cations. These two crystals are predicted to be thermodynamically stable at pressures above 30 GPa for (NH_{4})(N_{5}) and 50 GPa for pentazole N_{5}H. The chemical transformation of ammonium azide (NH_{4})(N_{3}) mixed with di-nitrogen (N_{2}) to ammonium pentazolate (NH_{4})(N_{5}) is predicted to become energetically favorable above 12.5 GPa. To assist in identification of newly synthesized compounds in future experiments, the Raman spectra of both crystals are calculated and mode assignments are made as a function of pressure up to 75 GPa

    Migrant workers in Rochdale and Oldham

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    This research focuses on the needs and experiences of Central and Eastern European migrants living and working in Rochdale and Oldham. It was commissioned by Oldham Housing Investment Partnership, Oldham Metropolitan Borough Council, Oldham Rochdale Housing Market Renewal Pathfinder and Rochdale Metropolitan Borough Council in January 2008 and was conducted by a team of researchers from the Salford Housing & Urban Studies Unit (SHUSU) at the University of Salford
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